Ratchet wheel device for a balance wheel clock

ABSTRACT

A RATCHET WHEEL MECHANISM FOR A WATCH OR CLOCK HAVING A COMMON SHAFT WITH A BALANCE WHEEK WITH A PERMANENT MAGNET AND OF WHICH A PAWL WHEEL, AND THE RATCHET WHEEL WITH DRIVE ARE COMPOSED ON AN ANTI-MAGNETIC MATERIAL RESISTANT TO WEAR.

NOV. 16, 1971 w, GANTER ETAL 3,620,005

RATCHET WHEEL DEVICE FOR A BALANCE WHEEL CLOCK Filed 001;. 2, 1968 l I E INVENTOM w fqmqg Gan-Li er Heinz 0X80 man Filed Oct. 2, 1968, Ser. No. 764,450 Claims priority, applicfation Germany, Oct. 4, 1967,

Int. Cl. G04c 3/04 US. CI. 5828 D 3 Claims ABSTRACT OF THE DISCLOSURE A ratchet wheel mechanism for a watch or clock having a common shaft with a balance wheel with a permanent magnet and of which a pawl wheel, and ratchet wheel with drive are composed of an anti-magnetic material resistant to wear.

The invention relates to a ratchet wheel device for a balance wheel watch or clock, preferably with a balance wheel carrying a permanent magnet arrangement, and consisting of a ratchet wheel, a pawl wheel and a ratchet wheel drive, which have been arranged on a common shaft.

The ratchet wheel arrangement in the case of a balance wheel watch or clock is in the immediate vicinity of the balance wheel. If the elements of the ratchet wheel arrangement consist of ferromagnetic material, then the possibility exists that the balance wheel could be influenced by a magnetic field, and to be sure especially in those cases where one is dealing with a balance Wheel with a permanent magnet arrangement, as is customarily used in the case of balance wheel oscillators driven without contact by electromagnetic means. The ratchet wheel parts can be made for example of brass, but a brass shaft for example, does not have good running characteristics in brass plates. Also, brass is not resistant enough for the stress exerted on several parts of the arrangement.

The present invention is based on the object of creating a ratchet wheel arrangement of the type mentioned which will practically not influence the balance wheel and which can be produced at the same time in a simple manner and which has a useful life. According to the invention, this will be achieved by the fact that the ratchet wheel shaft with drive, the ratchet wheel, and pawl wheel consist preferably of different anti-magnetic materials which are resistant to wear and tear. The ratchet wheel shaft with drive can consist of bronze or copper-beryllium, and preferably also with the pawl wheel, can be composed of a plastic injection molded part.

The ratchet wheel itself consists preferably of copperberyllium, but it is also possible to make the ratchet wheel from titanium or eloxate aluminum or other metals and alloys.

The pawl wheel may consist of brass, aluminum or other metals. The pawl wheel preferably has several stamped on pins on which the ratchet wheel is disposed.

The retaining spring engaging with the ratchet wheel is preferably arranged on small posts attached with frictional contact on a workplate, which posts have at least two diametrically opposed planes on its jacket surface to which a tool can be applied so that the small United States Patent 3,620,005 Patented Nov. 16, 1971 posts can be turned in a simple manner and thus the retaining spring can be adjusted.

Further objects will be apparent from the following description when considered in connection with the accompanying drawing in which;

FIG. 1 is a plan view partly in section showing the arrangement of a ratchet wheel according to the invention, and

FIG. 2 is a side 'view partly in section of the arrangement according to FIG. 1.

Referring to the drawing, numbers 10 and 11 designate the work-plates between which the balance wheel shaft 12 is mounted in bearing bolts 13 and 14. The balance wheel or body is 16, and 17 is a permanent magnet with the return or back plates 18 and 19 provided as shown. A coil arrangement not shown in the drawing projects into the air gap between the permanent magnet 17 and the return plate 19.

On the balance wheel 16 there is attached an angular switching spring 20 which switches or moves the ratchet wheel 24 one tooth further at each oscillation.

The ratchet wheel shaft 22 is mounted on the bearing plates 10 and 11, which shaft preferably consists of one piece with a drive member 23, preferably made of copper-beryllium. The ratchet wheel shaft with the drive 23 and/or pawl wheel 25 can also be made as a plastic injection molded part. In order to achieve good bearing qualities, it will also be possible to inject or insert a metal core into the plastic injection molded part.

The pawl wheel 25 has been forced onto the shaft 22 by pressure, and preferably, it consists of brass but it can be made of aluminum. In order to achieve a simple construction, the pawl wheel 25 has been provided with stamped-out or projecting pins 25a, onto which the ratchet wheel 24 provided with corresponding recesses, can be forced by pressure. The ratchet wheel 24 also consists preferably of copper-beryllium, but it can also consist of titanium or eloxate aluminum and other metals.

It has turned out that in the case of the use of the materials enumerated for the individual parts of the ratchet wheel device, good running characteristics and a long useful life of the individual parts will be achieved.

A retaining spring 26 engaging with the pawl wheel 25, has been arranged on a small post 27, which has been inserted with frictional contact in the workplate 11. The small post 27 has been provided with milled planes 27a and 27b, or it consists of a profile material, for example square or hexagonal material, as a result of which the possibility is produced to twist the little post with the assistance of a tool in the workplate 11, and thus to adjust the retaining spring 26.

Also, the shifting spring 20 can be attached in a small post 21, which has been inserted with frictional contact in the balance wheel 16. The small post 21 also has been provided preferably with a milled plane surface 21a which makes possible the application of a tool.

We claim:

1. A drive mechanism for a clock, comprising:

a shaft,

a balance wheel having a permanent magnet mounted on said shaft,

a second shaft of an anti-magnetic material mounted parallel to said first shaft and including an integral ratchet wheel drive thereon,

a pawl wheel mounted to said second shaft and including a plurality of upstanding pins,

a ratchet wheel mounted by said pins to said pawl wheel, and

4- said pawl wheel and ratchet wheel are made of an References Cited 2 f i' l f l 1 f th UNITED STATES PATENTS rive mee anism as in c a1m ur er comprising a post spaced from said second shaft, said post hav- 5 2g??? g i ing two diametrically opposed plane faces, 5 cppe em a an e t ecelvmg i and STEPHEN J. TOMSKY, Primary Examiner a retaining spring mounted to said post and engaging said pawl Wheel whereby said retaining spring is SIMMONS, Assistant Examiml adjusted by twisting said post in said aperture. 3. A driving mechanism as in claim 1 wherein said 10 second shaft, said ratchet wheel drive and said pawl 31O 37 wheel are made from an extruded plastic material. 

